Gem dop



J. LUDEL Feb. 17, 1948,

GEM DOP Filed Oct. 23, 1944 ATTORNEY 4 w "A 5 w v]. A 2 v w 4 M E h 2 4 M 2 MM DI! mo v 2 4 m4 4 4a 1 @444 5 2 4 Y 4 x a 5 I u r- H 5 K FJ w m l 53 3 4 0O 2 n y Q T- l 0 Q 1 4 5 53 WHHI 5w 4 MM. 35 9 5 4 2 Li 4 7 1 2, I

Patented Feb. 17, 1948 Jacob Ludel; New York, N. Y;;c-asgnorfto" Diemond Craft of- America, Inc; New York; N. Y.;" a corporation of Delaware Application October-.123,1944,15,?

:This invention relates to dops, more particularly to dops useful in forming girdle facets on gems; and still more particularly for the formationof girdle facets on brilliant-cut type'dia monds.

-My invention is an improvement of the dop shown in the application of William Ludel, Serial No. 516,337, filed December 31, 1943, and has utility also in connection with my invention for Method for grinding gems and apparatustherefor filed on even'date herewith. j

It is an object of my invention to provide a gem dop for simplifying the operation of imposing facets uponthe girdle of gems; more particue larly, faceting of the girdle forming portion of diamonds; and still more particularly, the girdle of brillianteered brilliant-cut diamonds.

' Still more particularly, it is an object of my invention to provide a dop for performing girdle faceting operations on gems, more particularly diamonds, which satisfies the rigid requirements of, accurately positioning the girdle or periphery of, the diamond at right angles to the staff of the dopjior' indexing of the girdle in relation to the movable jaws, providing a construction which is capable of assembly quickly, and which involves economy of construction and assembly.

jTo attain theseobjects and such further objects as may appear herein or be hereinafter pointed out,I make reference to the accompanying drawing forming a part hereof, in which Figure l is a plan view illustrating my dop, with portions broken away and shown in section; J Figure2 is a section taken on the line 2-2 of Figu're'l; i Figure Bis a section taken on the line 3-3 of Figure'2; I

Figure 4 is a fragmentary side view;

Figure 5 is a section taken on the line 5-5 of Figure 2.' f

Making"rference to the drawinamy dop Ill comprisesa block or'body portion ll to theback l2 of which mares screw-threaded one end 'of "a stafi or. spindle l3fhav'ing a'sho'ulder l4. This st'afibr spindle isdesigned to rotate within a positioning sleeve (not shown) whose axis is 'ver-. tieal andintersects'the' operative horizontal S111". faceof 'a rotary skeif or polishing lap." When so mounted the dop may be turned to present the grain of the diamond at its girdle, portion, ,ior best effective polishing operation in forming the girdle facets, in the manner well understood by those skilled'in'the art, and for other purposes described in said William Ludel application.

The block H has a guide surface l5, accurately 4 Claims. (01.51 229? 1 formed 'atright' glesto'the axial line through the stafll3;.--

With this construction "I provide jawsl 6and' ll," eachformed with a nose portion I 8' and l3,

" respectively, the nose portions having'bearing bores 20 :1 and f- 2 I"; respectively. These bearing bores 'are'accurate1yi aligned, th'ebor'e 20 receiv ing thespindle 22"ofthefadaptenfl which en' gagesthe diamond crow'nr Thebearing bore2l receives the indexing spindle of theadapter whichengages' the paviliiin" of the diamond.

Eachof th'eadapt'ers 23-and 25 has ashoulder 26 :and Z'L'irespctively, to'engage' the facesZB and28 of the'jaws'l 6 and 11'; inthe mannermore particularly "described in the William Ludel ap' plication aforementioned.

Each of the jaws l6 and 11 has a bearing sur-L face 30 and 3|, respectively arranged'to engage the guide surface 1 iii-Coir the bearing block. Each of the jaws, ISTfiIl-dlT-HS desirably formed with a horizontal, shoulder "32' and 33 respectively," dis posed at opposite sides of the neck 34;

With'the-construction as described, I provide guide-plates 35; 35, the upper 'portionsof which are provi dedxwith flanges 31 and 38, respectively. arranged to contact the shoulders 32 and 33, respectively, and definejja slot 33, through which the necks 3410f thejaws I6 and I! project.

The' plates 35*and-36are provided with stop flanges-4p and 4|, respectively, thereby limiting outward movement of the jaw H. The jaw I1 carries a horizontal stud 42, the head of which 43 is.-'anchored -ifi the outer face of the jaw ll. Theshan'kT or the stud .42 is screw threaded. The jaw i6 is provided with a horizontal bore 45 through which, pitends a sleeve 46 constituting a'portionof an adjusting member 41. The sleeve 46 is internally 's'crew threaded at 48 for engage: ment with the threaded shank 44 of the stud 42. The nut 41' is provided with an' annular slot between a radial collar 5Q anda shoulder 5 I While the assembly comprising the housing defined by'theparts 35 and36, the jaws i6 and ll, the stud'42; and the adjusting member 43 is held conveniently in one hand, the operator may readily; move the jaws lfi and I1 and the -adapters 23 and 25 carried by the jaws relatively to a diamond D'thus affording easy manipulation of the diamond-stock for properly locating it be tween the'adapters, without the necessity for manipulation of the adjusting nut 41.

When oneor mor'e'diamcnds, as when stacking a plurality of such diamonds with filler blocks therebetweenasin my companion application; are axially mountedb'etween the adapters 23 and 3 25, the above assembly may be mounted on the block II. For this purpose each of the plates 35 and 36 is provided with a pair of parallel guide slots 52', 52 to receive the shanks 53 of the headed screws 54 projecting from opposite sides of the body portion II.

The body portion or block I I has at its edge 55 an anchor plate 56, held in position by the screws 51. The plate 56 is formed with fingers 58, 58, defining a slot 59.

With the construction described, the operator aligns the slots 52, 52 over the shanks of the screws 54, adjusting the nut 41 so that the fingers 58 enter the slot 49 until the bearing surfaces 3|] and 3| contact the guide surface I5 of the block II. In this position, the screws 54 are each tightened. Thereupon the adjusting nut 41 may be manipulated for drawing the jaws I6 and I! to and from each other, either for fixedly clamping the diamond D within the adapters 23 and 25 against rotation, or slightly releasing the jaws I6 and I! from each other to an extent to permit indexing of the diamond, to expose different portions of the girdle to the skeif or polishing surface.

By my construction, I have provided a dop which simplifies the element of manipulation of the jaws in axially aligning the diamond stock between the adapters held by the jaws I6 and I1. Also, considerable economy in labor is effected in the simplification of the machining operations necessary for constructing the various parts.

The ability to draw the jaws I'Iiv and I1 toward eachother without screw feeding when the jaws IE and I! are disengaged from the block II will readily appeal to the skilled diamond worker who has to adjust the diamond stock in the adapters for this purpose.

It will thus be observed that I have provided a dop particularly valuable in connection with accurately axially aligning the diamond, to perform the girdle faceting operation.

It will also be observed that by my construction all clearance tolerance and play between the block I I and the jaws l6 and I! may be taken up by the guide plates, as by tensioning of the screws 54 against the guide plates, after securely urging the jaws into firm contact with the guide surface I5. Likewise, manipulation of the screws 51, 5'! may be resorted to for adjustment of the anchor plate and the adapter jaws.

In this way a highly accurate arrangement of the dop is secured, notwithstanding the mobility of the parts for assembly, for the adjustments necessary in practicing the girdle faceti operations, and the indexing necessary to rotate the adapters between which the diamond is mounted.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. A dop for use in forming girdle facets on a brilliant cut diamond, said dop comprising a body portion secured to one end of a dop-positioning staff, and a diamond-holding assembly detachably secured to the body portion, said assembly including a housing defining a guideway for a pair of relatively movable work-holding jaws provided with work-engaging elements, a screwthreaded stud fixed at one end to one of said jaws, a rotatable adj sting member havingan internally screw-threaded sleeve portion which receives the free end of the stud, the adjusting member passing freely through a bore in the other jaw whereby the jaws may be slid freely toward and from each other while the assembly is dismounted from the body portion of the dop, thereby facilitating the positioning of a diamond between the work-engaging elements of the jaws, and means for detachably securing the assembly to the body portion of the dop, the body portion and the adjusting member having interengageable parts operative to prevent axial movement of the adjusting member when the assembly is operatively mounted on the body portion of the dop 2. A dop for use in forming girdle facets on a brilliant cut diamond, said dop comprising a body portion secured to one end of a dop-positioning staff, and a diamond-holding assembly detachably secured to the body portion, said assembly including a housing defining a guidway for a pair of relatively movable work-holding jaws provided with work-engaging elements, a screwthreaded stud fixed at one end to one of said jaws, a rotatable adjusting member having an inter, nally screw-threaded sleeve portion which receives the free end of the stud, the adjusting member passing freely through a bore in the other jaw whereby the jaws may be slid freely toward and from each other while the assembly is dismounted from the body portion of the dop, thereby facilitating the positioning of a diamond between the work-engagin elements of the jaws, and means Operative, when the assembly is mounted on the body portion of the dop, to clamp the jaws against relative movement.

3. A dop for use in iorming girdle facets ona brilliant, Cut diamond, said dop comprising a body portion secured to one end of a dop-positioning staff, and a diamond-holding assembly detach.- ably secured to the body portiomsaid assembly cluding a housin defini a g d fo a p r o relat ely m vable Wo k-h ld n ws proi d with ork-en a in el ments, a r w: threaded stud fixed at one end to one of said jaws. a rota abl adjustin mem er havi n e n ly cre ih eaii d s ee e portion. which r i es he free and Q the s u t e adjustin m r pa si g r ely hr u a bo e i the other Ja whereb the jaws ma h slid reely w d and m ach the W il th embly i di mou ted from he bady rt o of he den. h r b faci tatin the o itionin o a d amond between he w k-enga ing lemen of t e jaw and a s ope at e. afte the assembly hasbeen ed to th d po tion of th d p. o cl mp a d fix e adins iii imem en 4. A dop for use in a machine for faceting the i d of a d a o who e cr w and Pavi io facets have already been formed, the dop having. a fi i d t iirnabvi-it a a i radial spac d f m but para le t t e a s of a rotati lap whereby the grain of the diamond may be, arranged most advantageously for cutting with respect .to the Operative surface of the lap, chara t i ed n ha t e d com s s a rigid bl ck having a rectilinear guide surface perpendicular to t ax s f r a on of th d an assemb whi h is r m l a a u i from h bloc nd hich ompr e a pa r o aws liitha e f el mo able to ard and i omv each othe w n t e assembly is .senarate i qm the block. e ch J w hav sa suppo t for a rotatablepart ca r g a diamo d-e ga n el ment ilie ax of s 1 v-- n t ein a ned and the diam nd-en ag ng elements being opposed and adapted, by aliproach of the jaws, to grip adiamond between h m. th s mb y a so in ud n a ho i o REFERENQES. CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS I Name Date Beers June 1. 1886 15 Number Number Number Name Date Fulmer et a1 June 30, 1891 Lobbett Mar. 24, 1925 Hessels Nov, 15, 1881 Rennie Dec. 30, 1919 Hornig Sept, 13, 1910 Weaver Oct. 16, 1900 Stenvall May 23, 1916 Maynard July 16, 1929 Lilljiquist Nov. 15, 1910 FOREIGN PATENTS Country Date France Nov. 2, 1923 

